1. Field of the Invention
The present invention relates to an automotive headlamp apparatus used in, for example, vehicles, and a method of controlling an automotive headlamp apparatus.
2. Description of the Related Art
Generally, an automotive headlamp apparatus is capable of switching between a low beam and a high beam. A low beam is for illuminating an area close to, for example, a vehicle with a predefined intensity. Distribution of a low beam is subject to provisions that provide for prevention of glare as experienced by oncoming vehicles or vehicles in front. A low beam is primarily used on city streets. A high beam is for illuminating wide areas ahead and distant areas with a relatively high illumination intensity. A high beam is primarily used for high-speed driving on a road with relatively few oncoming vehicles and vehicles in front. As such, a high beam is superior to a low beam in respect of visibility for the driver. However, a high beam has a disadvantage of causing the driver of a vehicle or pedestrian ahead of the illuminating vehicle to experience a glare.
This is addressed by a known technology for reducing a glare as experienced by vehicles or pedestrians by, for example, reducing illumination in an area corresponding to a vehicle or pedestrian when the vehicle or pedestrian is detected in a high beam distribution pattern while a high beam is being used (JP 2005-329819).
We have come to be aware of the following problem. While a low beam is usually used for night driving in city districts, the light source for a high beam is not used while a low beam is being used. Meanwhile, there is always a need to improve the visibility of a road for the driver while a low beam is being used.